Embodiments of the subject matter relate generally to semiconductor devices and, more particularly, to three-dimensional semiconductor memory devices and methods of fabricating the same.
Due to their small size, multifunctional capabilities and/or low cost, semiconductor devices are important elements in the electronic industry. Higher integration of semiconductor devices is desired to satisfy consumer demands for superior performance and lower cost. In the case of semiconductor memory devices, since their integration is an important factor in determining product prices, increased integration is especially desirable.
In typical two-dimensional or planar semiconductor memory devices, the degree of integration is generally limited by the area occupied by a unit memory cell, which may be limited by fine pattern forming technology. In particular, the expense of process equipment needed to increase pattern fineness may act as a practical limitation on increasing integration for two-dimensional or planar semiconductor memory devices. To overcome such a limitation, there have been recently proposed three-dimensional semiconductor memory devices having multiple layers of memory cells.